Dunno if a humidity of 65% has anything to do with it, but it's often advised to keep it between 50 and 60.
Also, the plant that is doing the worse is directly next to the humidifier. That may play a role as that plant might be affected by even higher humidity than just 65%.
Try moving it further away from the humidifier for a few days and see how the new growth comes out.
Besides that, what is your watering schedule? Might you be overwatering?